Liquid Crystal Displays (LCDs) are one of electronic products having the most potential to develop in the field of displays. They have various substantive advantages including low driving voltage, low power consumption, light weight, no harmful rays, and the like. LCD display depends on different arrangements of liquid crystal molecules after anisotropic treatment of the surface film of substrate. Of those, the layer of liquid crystal molecules are the most important portion for changing the polar status of light.
During the manufacture of LCD, a minor amount of metal ions will be unavoidably introduced into the liquid crystal molecule layer due to a variety of external factors so that the polar ends of the liquid crystal molecular layer are highly easy to be absorbed by the metal ions. When the polar ends of the liquid crystal molecules are absorbed by the metal ions, the polar differences between two ends of the liquid crystal molecules will accordingly reduced. When an electric field is applied, the liquid crystal molecular layer will fail to twist because of the similar polarities at both ends so that the liquid crystal molecules are polarized to cause residual images in liquid crystal panel.
For preventing the polarization of liquid crystal molecules, the currently used methods are commonly based on circuit, i.e., incorporating a specific functional circuit into the drive circuit in the liquid crystal panel so as to prevent the metal ions in the liquid crystal molecular layer from assembling towards a single direction. However, when carrying out the aforesaid methods, the inventors find that the circuit design cannot improve fundamentally the polar difference between both ends of the liquid crystal molecules, but merely induce the twist of metal ions, and thus any abnormal power supply or abnormal controlling signing output taking place in the circuit will interrupt the twist of metal ions, and cause unavoidably the polarization of the liquid crystal molecules.
Based on the above background and demands, the present inventors develop a liquid crystal aligning agent which solves the problem of residual images in liquid crystal panels even under an electric field by means of preventing the liquid crystal molecules from polarization.